Electronic device and method for transmitting and receiving wireless power

ABSTRACT

An electronic device and method for transmitting and receiving a wireless power are provided. An electronic device for transmitting and receiving wireless power may include a resonator configured to operate, based on a plurality of operating modes of the electronic device including a power reception mode, a relay mode, and a power transmission mode, wherein: (i) in the power reception mode, the resonator is configured to receive power from a wireless power transmitter, (ii) in the relay mode, the resonator is configured to relay power received from the wireless power transmitter to a wireless power receiver, and (iii) in the power transmission mode, the resonator is configured to transmit power to the wireless power receiver; and a path controller configured to control at least one electrical pathway of electronic device based on the operating mode.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit under 35 U.S.C. §119(a) of KoreanPatent Application No. 10-2011-0050402, filed on May 27, 2011, in theKorean Intellectual Property Office, the entire disclosure of which isincorporated herein by reference for all purposes.

BACKGROUND

1. Field

The following description relates to transmitting and receiving wirelesspower.

2. Description of Related Art

Wireless power refers to energy that is transferred from a wirelesspower transmitter to a wireless power receiver through magneticcoupling. Typically, a wireless power transmission and charging systemincludes a source device and a target device. The source device maywirelessly transmit a power, and the target device may wirelesslyreceive a power. The source device may be referred to as a wirelesspower transmitter, and the target device may be referred to as awireless power receiver.

The source device includes a source resonator, and the target deviceincludes a target resonator. Magnetic coupling or resonance coupling maybe formed between the source resonator and the target resonator.

SUMMARY

According to one general aspect, an electronic device for transmittingand receiving wireless power may include: a resonator configured tooperate, based on a plurality of operating modes of the electronicdevice including a power reception mode, a relay mode, and a powertransmission mode, wherein: (i) in the power reception mode, theresonator is configured to receive power from a wireless powertransmitter, (ii) in the relay mode, the resonator is configured torelay power received from the wireless power transmitter to a wirelesspower receiver, and (iii) in the power transmission mode, the resonatoris configured to transmit power to the wireless power receiver; and apath controller configured to control at least one electrical pathway ofelectronic device based on the operating mode.

The electronic device may further include: a power converter configuredto convert direct current (DC) voltage to alternating current (AC)voltage using a resonance frequency, and to transfer the AC current tothe resonator, when the electronic device is operated in the powertransmission mode.

The electronic device may further include: a power amplifier configuredto amplify the DC voltage.

The electronic device may further include: a rectification unitconfigured to generate a DC signal by rectifying an AC signal of a powerreceived via the resonator, when the electronic device is operated inthe power reception mode.

The electronic device may further include: a DC-to-DC (DC/DC) converterconfigured to supply voltage of a predetermined level to a load byadjusting a level of the DC signal.

The electronic device may further include: a control/communication unitconfigured to perform a communication with the wireless powertransmitter or the wireless power receiver, to determine the operatingmode by the communication, to control the path controller based on thedetermined operating mode, or any combination thereof.

The resonator may be configured to receive the power from the wirelesspower transmitter by passing through one or more electronic devices.

The resonator may be configured to transmit the power to the wirelesspower receiver by passing through one or more electronic devices.

The resonator may be configured to simultaneously transmit the power toa plurality of electronic devices.

The electronic device may further include: a control/communication unitconfigured to control a magnetic field to be uniformly distributed,based on a direction of an induced current flowing in the resonator, andon a direction of an input current flowing in a feeding unit, whereinthe magnetic field is formed in the resonator.

According to another general aspect, a method for transmitting andreceiving wireless power in an electronic device may include:determining one of a plurality of operating modes of the electronicdevice, the plurality of operating modes of the electronic deviceincluding a power reception mode, a relay mode, and a power transmissionmode; and (i) in the power reception mode, receiving power from awireless power transmitter, (ii) in the relay mode, relaying powerreceived from the wireless power transmitter to a wireless powerreceiver, and (iii) in the power transmission mode, transmitting powerto the wireless power receiver.

The method may further include: performing a communication with anotherelectronic device to determine the operating mode of the electronicdevice.

The method may further include: supplying voltage of a predeterminedlevel to a load by adjusting a level of a DC signal.

The method may further include: generating power using a resonancefrequency; and transferring the generated power to a resonator.

The method may further include: generating a DC signal by rectifying anAC signal of power received via a resonator.

The method may further include: receiving the power from the wirelesspower transmitter by passing through one or more electronic devices.

The method may further include: transmitting the power to the wirelesspower receiver by passing through one or more electronic devices.

The method may further include: simultaneously transmitting the power toa plurality of electronic devices.

According to yet another aspect, a resonator device may include: afeeder configured to receive an input current and to form a magneticfield; and a resonator configured to form another magnetic field basedon an induced current generated by the magnetic field of the feeder,wherein, when the magnetic field formed by the feeder and the anothermagnetic field formed by the source resonator are combined, the strengthof the combined magnetic field changes within the feeder and outside thefeeder.

The strength of the combined magnetic field may decrease within thefeeder and increase outside the feeder; or the strength of the combinedmagnetic field may increase within the feeder and decease outside thefeeder.

The resonator and the feeder have a common ground.

The resonator may include a capacitor.

The feeder may be electrically connected to the capacitor.

The feeder may be positioned at least partially within the resonator.

The resonator may have a closed loop structure.

The resonator may include: a first transmission line comprising a firstsignal conducting portion, a second signal conducting portion, and afirst ground conducting portion, the first ground conducting portioncorresponding to the first signal conducting portion and the secondsignal conducting portion; a first conductor electrically connecting thefirst signal conducting portion to the first ground conducting portion;a second conductor electrically connecting the second signal conductingportion to the first ground conducting portion; and at least one firstcapacitor inserted between the first signal conducting portion and thesecond signal conducting portion, in series with respect to a currentflowing through the first signal conducting portion and the secondsignal conducting portion.

The feeder may include: a second transmission line comprising a thirdsignal conducting portion, a fourth signal conducting portion, and asecond ground conducting portion, the second ground conducting portioncorresponding to the third signal conducting portion and the fourthsignal conducting portion; a third conductor electrically connecting thethird signal conducting portion to the second ground conducting portion;a fourth conductor electrically connecting the fourth signal conductingportion to the second ground conducting portion; a fifth conductorelectrically connecting the first signal conducting portion to the thirdsignal conducting portion; and a sixth conductor electrically connectingthe second signal conducting portion to the fourth signal conductingportion.

The resonator device may further include: a control/communication unitconfigured to control the magnetic field to be uniformly distributed,based on a direction of an induced current flowing in the resonator, andon a direction of an input current flowing in the feeder.

The controller may be configured to adjust the size of the feeder.

The resonator device may further include a matching device configured tomatch the input impedance to an output impedance.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a wireless power transmission andcharging system.

FIG. 2 is a diagram illustrating an electronic device.

FIGS. 3A and 3B are diagrams illustrating a distribution of a magneticfield in a feeder and a source resonator.

FIGS. 4A and 4B are diagrams illustrating a wireless power transmitter.

FIG. 5A is a diagram illustrating a distribution of a magnetic fieldwithin a source resonator based on feeding of a feeding unit.

FIG. 5B is a diagram illustrating equivalent circuits of a feeding unitand a source resonator.

FIG. 6 is a diagram illustrating another wireless power transmitter.

FIG. 7 is a diagram illustrating still another wireless powertransmitter.

FIGS. 8A through 13B are diagrams illustrating various resonators.

FIG. 14 is a diagram illustrating one equivalent circuit of a resonatorof FIG. 8A.

FIG. 15 is a diagram illustrating a method for transmitting andreceiving wireless power.

FIGS. 16 and 17 are diagrams illustrating a method for transmitting andreceiving wireless power between electronic devices.

FIG. 18 is a diagram illustrating an electric vehicle charging system.

FIG. 19 is a diagram illustrating a wireless power transmission methodof an electric vehicle.

Throughout the drawings and the detailed description, unless otherwisedescribed, the same drawing reference numerals will be understood torefer to the same elements, features, and structures. The relative sizeand depiction of these elements may be exaggerated for clarity,illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the methods, apparatuses,and/or systems described herein. Accordingly, various changes,modifications, and equivalents of the methods, apparatuses, and/orsystems described herein will be suggested to those of ordinary skill inthe art. The progression of processing steps and/or operations describedis an example; however, the sequence of and/or operations is not limitedto that set forth herein and may be changed as is known in the art, withthe exception of steps and/or operations necessarily occurring in acertain order. Also, description of well-known functions andconstructions may be omitted for increased clarity and conciseness.

FIG. 1 illustrates a wireless power transmission and charging system.

As shown, the wireless power transmission and charging system includes asource device 110, and a target device 120.

The source device 110 may include an alternating current-to-directcurrent (AC/DC) converter 111, a power detector 113, a power converter114, a control/communication unit 115, an impedance adjusting unit 117,and a source resonator 116.

The target device 120 may include a target resonator 121, arectification unit 122, a DC-to-DC (DC/DC) converter 123, a switch unit124, a charging unit 125, and a control/communication unit 126.

The AC/DC converter 111 may generate a DC voltage by rectifying an ACvoltage (e.g., in a band of tens of hertz (Hz)) output from a powersupply 112. The AC/DC converter 111 may be configured to output a DCvoltage of a predetermined level, and/or to adjust an output level of aDC voltage based on the control of the control/communication unit 115.

The power detector 113 may detect an output current and an outputvoltage of the AC/DC converter 111, and may transfer, to thecontrol/communication unit 115, information on the detected current andthe detected voltage. Additionally or alternatively, the power detector113 may detect an input current and an input voltage of the powerconverter 114.

The power converter 114 may be configured to convert DC voltage of apredetermined level to AC voltage, for instance, using a switching pulsesignal (e.g., in a band of a few megahertz (MHz) to tens of MHz). Otherfrequencies of AC power are also possible. In some implementations, thepower converter 114 may convert a DC voltage supplied to a poweramplifier to an AC voltage, using a reference resonance frequencyF_(Ref), and may output power.

The impedance adjusting unit 117 may include a plurality of, e.g., N,matching switches connected to a plurality of capacitors. The impedanceadjusting unit 117 may adjust an impedance of the source resonator 116by turning ON or OFF the N matching switches. The impedance adjustingunit 117 may include a Pi matching circuit or a T matching circuit, insome instances.

The control/communication unit 115 may be configured to detect areflected wave of a transmission power, and may detect mismatchingbetween the target resonator 121 and the source resonator 116 based onthe detected reflected wave. To detect the mismatching, thecontrol/communication unit 115 may detect an envelope of the reflectedwave, detect a power amount of the reflected wave, or both.

The control/communication unit 115 may calculate and/or compute avoltage standing wave ratio (VSWR), based on a voltage level of thereflected wave, and based on a level of an output voltage of the sourceresonator 116 or the power converter 114. For example, if the VSWR isless than a predetermined value, the control/communication unit 115 maydetermine that the mismatching is detected. For example, thecontrol/communication unit 115 may turn ON or OFF the N matchingswitches, may determine a tracking impedance Im_(Best) with an optimalor the best power transmission efficiency, and may adjust the impedanceof the source resonator 116 to the tracking impedance Im_(Best).

Additionally or alternatively, the control/communication unit 115 may beconfigured to adjust a frequency of a switching pulse signal. Under thecontrol of the control/communication unit 115, the frequency of theswitching pulse signal may be determined. And, by controlling the powerconverter 114, the control/communication unit 115 may generate amodulation signal to be transmitted to the target device 120. Also, thecontrol/communication unit 115 may transmit various messages to thetarget device 120 using in-band communications. Moreover, thecontrol/communication unit 115 may detect a reflected wave, and maydemodulate a signal received from the target device 120 through anenvelope of the detected reflected wave.

The control/communication unit 115 may generate a modulation signal forin-band communication, using various schemes. To generate a modulationsignal, the control/communication unit 115 may turn ON or OFF aswitching pulse signal, and/or may perform delta-sigma modulation.Additionally or alternatively, the control/communication unit 115 maygenerate a pulse-width modulation (PWM) signal with a predeterminedenvelope.

The control/communication unit 115 may perform out-band communicationusing a communication channel. The control/communication unit 115 mayinclude a communication module, for example, configured to handleZigBee, Bluetooth, Wi-Fi, Wi-max, near field communication (NFC), radiofrequency identification (RFID), and/or other communication protocols.The control/communication unit 115 may transmit or receive data to orfrom the target device 120 using the out-band communication.

The source resonator 116 may be configured to transfer electromagneticenergy to the target resonator 121. For example, the source resonator116 may transfer, to the target device 120, communication power used forcommunication, charging power used for charging or both, using amagnetic coupling with the target resonator 121.

The target resonator 121 may receive electromagnetic energy from thesource resonator 116. For example, the target resonator 121 may receive,from the source device 110, the communication power and/or the chargingpower using the magnetic coupling with the source resonator 116.Additionally or alternatively, the target resonator 121 may receivevarious messages from the source device 110 using the in-bandcommunication.

The rectification unit 122 may generate a DC voltage by rectifying an ACvoltage. For instance, the AC voltage may be received from the targetresonator 121.

The DC/DC converter 123 may be configured to adjust a level of the DCvoltage output from the rectification unit 122 based on a capacity ofthe charging unit 125. For example, the DC/DC converter 123 may adjust,from 3 to 10 volt (V), the level of the DC voltage output from therectification unit 122.

The switch unit 124 may be turned ON or OFF under the control of thecontrol/communication unit 126. When the switch unit 124 is turned OFF,the control/communication unit 115 of the source device 110 may detect areflected wave. Moreover, when the switch unit 124 is turned OFF, themagnetic coupling between the source resonator 116 and the targetresonator 121 may be eliminated.

In some embodiments, the charging unit 125 may include at least onebattery. The charging unit 125 may charge the at least one battery usinga DC voltage output from the DC/DC converter 123.

The control/communication unit 126 may perform in-band communication fortransmitting or receiving data using a resonance frequency, forinstance. During the in-band communication, the control/communicationunit 126 may demodulate a received signal by detecting a signal betweenthe target resonator 121 and the rectification unit 122, or detecting anoutput signal of the rectification unit 122. The control/communicationunit 126 may demodulate a message received using the in-bandcommunication.

Additionally or alternatively, the control/communication unit 126 mayadjust an impedance of the target resonator 121, to modulate a signal tobe transmitted to the source device 110. The control/communication unit126 may modulate the signal to be transmitted to the source device 110,for instance, by turning ON or OFF the switch unit 124. For example, thecontrol/communication unit 126 may increase the impedance of the targetresonator 121 so that a reflected wave may be detected from thecontrol/communication unit 115 of the source device 110. For example,depending on whether the reflected wave is detected, thecontrol/communication unit 115 may detect a binary number (e.g., “0” or“1.”)

The control/communication unit 126 may be configured to transmit aresponse message to the wireless power transmitter. The response messagemay include, for example, a “type of a corresponding target device,”“information on a manufacturer of a corresponding target device,” “amodel name of a corresponding target device,” a “battery type of acorresponding target device,” a “scheme of charging a correspondingtarget device,” an “impedance value of a load of a corresponding targetdevice,” “information on characteristics of a target resonator of acorresponding target device,” “information on a frequency band used by acorresponding target device,” an “amount of a power consumed by acorresponding target device,” an “identifier (ID) of a correspondingtarget device,” or “information on version or standard of acorresponding target device.”

The control/communication unit 126 may also perform out-bandcommunication using a communication channel. The control/communicationunit 126 may include a communication module, such as, one configured toprocess ZigBee, Bluetooth, Wi-Fi, Wi-Max and/or the like communications.The control/communication unit 126 may transmit or receive data to orfrom the source device 110 using the out-band communication, forinstance.

The control/communication unit 126 may be configured to receive awake-up request message from the wireless power transmitter, may detectan amount of a power received to the target resonator 121, and maytransmit, to the wireless power transmitter, information on the detectedamount of the power. The information on the detected amount may include,for example, an input voltage value and an input current value of therectification unit 122, an output voltage value and an output currentvalue of the rectification unit 122, an output voltage value and anoutput current value of the DC/DC converter 123, and the like.

The term “in-band” communication(s), as used herein, meanscommunication(s) in which information (such as, for example, controlinformation, data and/or metadata) is transmitted in the same frequencyband, and/or on the same channel, as used for power transmission.According to one or more embodiments, the frequency may be a resonancefrequency. And, the term “out-band” communication(s), as used herein,means communication(s) in which information (such as, for example,control information, data and/or metadata) is transmitted in a separatefrequency band and/or using a separate or dedicated channel, than usedfor power transmission.

FIG. 2 illustrates an electronic device 220.

As shown, the electronic device 220 includes a resonator 221, a powerconverter 228, a rectification unit 222, a DC/DC converter 223, a switchunit 224, a charging unit 225, a control/communication unit 226, and apath controller 227. The resonator 221 may be operated based on one of aplurality of operating modes of the electronic device 220 including apower reception mode, a relay mode, and a power transmission mode.

In the power reception mode, the resonator 221 may be configured as atarget resonator so as to receive power from a wireless powertransmitter (e.g., using a magnetic coupling). In the relay mode, theresonator 221 may be configured as a relay resonator so as to relaypower received from the wireless power transmitter to a wireless powerreceiver. And, in the power transmission mode, the resonator 221 may beconfigured as a source resonator so as to transmit power to the wirelesspower receiver (e.g., using the magnetic coupling).

When the electronic device 220 receives a power from another electronicdevice the resonator 221 may be operated as a target resonator. One theother hand, when the electronic device 220 transmits a power to anotherelectronic device, the resonator 221 may be operated as a sourceresonator.

In some embodiments, the electronic device 220 may be disposed betweenthe wireless power transmitter and the wireless power receiver and theresonator 221 may be operated as a relay resonator. When the resonator221 is used as a relay resonator, the resonator 221 may not be connectedto the power converter 228 and the rectification unit 222, and maymerely increase a range of magnetic coupling, a range of a wirelesspower transmission, or both.

The power converter 228 may perform the same or a similar function tothe power converter 114 of FIG. 1. For example, when the electronicdevice 220 is operated in a power transmission mode, the power converter228 may convert DC voltage to AC voltage using a resonance frequency,and may transfer the generated power to the resonator 221. And, the DCvoltage may be supplied from the charging unit 225 to a power amplifier.

The rectification unit 222 may perform the same or a similar function tothe rectification unit 122 of FIG. 1. For example, when the electronicdevice 220 is operated in a power reception mode, the rectification unit222 may generate a DC signal by rectifying an AC signal received via theresonator 221.

The DC/DC converter 223 may perform the same or similar function as theDC/DC converter 123 of FIG. 1. Accordingly, the DC/DC converter 223 maysupply voltage of a predetermined level to a load by adjusting a levelof a DC signal.

The path controller 227 may be configured to control a connection of theresonator 221, the power converter 228 and the rectification unit 222,based on the operating mode of the electronic device 220.

The switch unit 224 and the charging unit 225 may be configuredidentical or similar to the switch unit 124 and the charging unit 125 ofFIG. 1, respectively.

The control/communication unit 226 may perform a function of thecontrol/communication unit 115 of FIG. 1, a function of thecontrol/communication unit 126 of FIG. 1, or both. When the electronicdevice 220 is operated in the power transmission mode, thecontrol/communication unit 226 may be configured to perform the functionof the control/communication unit 115. On the other hand, when theelectronic device 220 is operated in the power reception mode, thecontrol/communication unit 226 may be configured to perform the functionof the control/communication unit 126.

The control/communication unit 226 may perform a communication with thewireless power transmitter or the wireless power receiver, may determinethe operating mode by the communication, and may control the pathcontroller 227, based on the determined operating mode.

FIGS. 3A and 3B illustrate a distribution of a magnetic field in afeeder and a source resonator.

If a source resonator 320 may receive power through a separate feeder310, magnetic fields may be formed in both the feeder and the sourceresonator.

Referring to FIG. 3A, as an input current flows in the feeder 310, amagnetic field 330 may be formed. The direction 331 of the magneticfield 330 within the feeder 310 may have a phase opposite to a phase ofa direction 333 of the magnetic field 330 outside the feeder 310. Themagnetic field 330 formed by the feeder 310 may cause an induced currentto be formed in the source resonator 320. The direction of the inducedcurrent may be opposite to a direction of the input current.

Due to the induced current, a magnetic field 340 may be formed in thesource resonator 320. Directions of a magnetic field formed due to aninduced current in all positions of the source resonator 320 may beidentical in some instances. Accordingly, the direction 341 of themagnetic field 340 formed by the source resonator 320 may have the samephase as a direction 343 of the magnetic field 340 formed by the sourceresonator 320.

Consequently, when the magnetic field 330 formed by the feeder 310 andthe magnetic field 340 formed by the source resonator 320 are combined,the strength of the total magnetic field may decrease within the feeder310; yet may increase outside the feeder 310. If power is supplied tothe source resonator 320 through the feeder 310 configured asillustrated in FIG. 3, the strength of the total magnetic field maydecrease in the center of the source resonator 320, but may increaseoutside the source resonator 320. And because the magnetic field may berandomly distributed in the source resonator 320, it may be difficult toperform impedance matching since the input impedance may frequentlyvary. Additionally, when the strength of the total magnetic field isincreased, an efficiency of wireless power transmission may beincreased. Conversely, when the strength of the total magnetic field isdecreased, the efficiency for wireless power transmission may bereduced. Accordingly, the power transmission efficiency may be reducedon average.

In a target resonator, a magnetic field may be distributed asillustrated in FIG. 3A. Current flowing in the source resonator 320 maybe induced by the input current flowing in the feeder 310. The currentflowing in the target resonator may be induced by a magnetic couplingbetween the source resonator 320 and the target resonator. The currentflowing in the target resonator may cause a magnetic field to be formed,so that an induced current may be generated in a feeder located in thetarget resonator. Within the feeder, a direction of a magnetic fieldformed by the target resonator may have a phase opposite to a phase of adirection of a magnetic field formed by the feeder and accordingly,strength of the total magnetic field may be reduced.

FIG. 3B illustrates a structure of a wireless power transmitter in whicha source resonator 350 and a feeder 360 have a common ground. The sourceresonator 350 may include a capacitor 351, in some instances. The feeder360 may receive an input of a radio frequency (RF) signal via a port361.

For example, when the RF signal is received to the feeder 360, an inputcurrent may be generated in the feeder 360. The input current flowing inthe feeder 360 may cause a magnetic field to be formed, and a currentmay be induced in the source resonator 350 by the magnetic field.Additionally, another magnetic field may be formed due to the inducedcurrent flowing in the source resonator 350. As shown, the direction ofthe input current flowing in the feeder 360 may have a phase opposite toa phase of the direction of the induced current flowing in the sourceresonator 350. Accordingly, in a region between the source resonator 350and the feeder 360, the direction 371 of the magnetic field formed dueto the input current may have the same phase as the direction 373 of themagnetic field formed due to the induced current, and thus the strengthof the total magnetic field may increase. Conversely, within the feeder360, the direction 381 of the magnetic field formed due to the inputcurrent may have a phase opposite to a phase of the direction 383 of themagnetic field formed due to the induced current, and thus the strengthof the total magnetic field may decrease. Therefore, the strength of thetotal magnetic field may decrease in the center of the source resonator350, yet may increase outside the source resonator 350.

The feeder 360 may determine the input impedance by adjusting aninternal area of the feeder 360. The input impedance here may refer toimpedance viewed in a direction from the feeder 360 to the sourceresonator 350. When the internal area of the feeder 360 is increased,the input impedance may be increased. Conversely, when the internal areaof the feeder 360 is reduced, the input impedance may be reduced. Sincethe magnetic field may be randomly distributed in the source resonator350 despite a reduction in the input impedance, a value of the inputimpedance may vary depending on a location of a target device.Accordingly, a separate matching network may be provided to match theinput impedance to an output impedance of a power amplifier. Forexample, when the input impedance is increased, the separate matchingnetwork may be used to match the increased input impedance to relativelylow output impedance.

In some implementations, such as, for example, when a target resonatorhas the same configuration as the source resonator 350, and when afeeder of the target resonator has the same configuration as the feeder360, a separate matching network may be required, because a direction ofa current flowing in the target resonator has a phase opposite to aphase of a direction of an induced current flowing in the feeder of thetarget resonator.

FIG. 4A illustrates a wireless power transmitter.

As shown in FIG. 4A, the wireless power transmitter may include a sourceresonator 410, and a feeding unit 420. The source resonator 410 mayinclude at least one capacitor 411. The feeding unit 420 may beelectrically connected to both ends of the at least one capacitor 411.

FIG. 4B illustrates, in more detail, the structure of the wireless powertransmitter of FIG. 4A. The source resonator 410 may include a firsttransmission line, a first conductor 441, a second conductor 442, and atleast one first capacitor 450. The first capacitor 450 may be inserted(e.g., in series) between a first signal conducting portion 431 and asecond signal conducting portion 432 in the first transmission line, andan electric field may be confined within the first capacitor 450. Forexample, the first transmission line may include at least one conductorin an upper portion of the first transmission line, and may also includeat least one conductor in a lower portion of the first transmissionline. Current may flow through the at least one conductor disposed inthe upper portion of the first transmission line, and the at least oneconductor disposed in the lower portion of the first transmission linemay be electrically grounded. For example, a conductor disposed in anupper portion of the first transmission line may be separated into andthereby be referred to as the first signal conducting portion 431 andthe second signal conducting portion 432. A conductor disposed in alower portion of the first transmission line may be referred to as afirst ground conducting portion 433.

As shown in FIG. 4B, the source resonator 410 may have a generallytwo-dimensional (2D) structure. The first transmission line may includethe first signal conducting portion 431 and the second signal conductingportion 432 in the upper portion of the first transmission line. Inaddition, the first transmission line may include the first groundconducting portion 433 in the lower portion of the first transmissionline. The first signal conducting portion 431 and the second signalconducting portion 432 may be disposed to face the first groundconducting portion 433 with current flowing through the first signalconducting portion 431 and the second signal conducting portion 432.

Additionally, one end of the first signal conducting portion 431 may beelectrically connected (i.e., shorted) to the first conductor 441, andanother end of the first signal conducting portion 431 may be connectedto the first capacitor 450. One end of the second signal conductingportion 432 may be electrically connected (i.e., shorted) to the secondconductor 442, and another end of the second signal conducting portion432 may be connected to the first capacitor 450. Accordingly, the firstsignal conducting portion 431, the second signal conducting portion 432,the first ground conducting portion 433, and the conductors 441 and 442may be connected to each other, so that the source resonator 410 mayhave an electrically closed-loop structure. The term “closed-loopstructure” as used herein, may include a polygonal structure, forexample, a circular structure, a rectangular structure, or the like thatis electrically closed.

The first capacitor 450 may be inserted into an intermediate portion ofthe first transmission line. For example, the first capacitor 450 may beinserted into a space between the first signal conducting portion 431and the second signal conducting portion 432. The first capacitor 450may be configured as a lumped element, a distributed element, or thelike. For example, a distributed capacitor may include zigzaggedconductor lines and a dielectric material that has a high permittivitybetween the zigzagged conductor lines.

When the first capacitor 450 is instead into the first transmissionline, the source resonator 410 may have a characteristic of ametamaterial. The metamaterial indicates a material having apredetermined electrical property that has not been discovered innature, and thus, may have an artificially designed structure. Anelectromagnetic characteristic of the materials existing in nature mayhave a unique magnetic permeability or a unique permittivity. Mostmaterials may have a positive magnetic permeability or a positivepermittivity.

In the case of most materials, a right hand rule may be applied to anelectric field, a magnetic field, and a pointing vector, and thus, thecorresponding materials may be referred to as right handed materials(RHMs). However, the metamaterial that has a magnetic permeability or apermittivity absent in nature may be classified into an epsilon negative(ENG) material, a mu negative (MNG) material, a double negative (DNG)material, a negative refractive index (NRI) material, a left-handed (LH)material, and the like, based on a sign of the correspondingpermittivity or magnetic permeability.

When a capacitance of the first capacitor 450 inserted as the lumpedelement is appropriately determined, the source resonator 410 may havethe characteristic of the metamaterial. Because the source resonator 410may have a negative magnetic permeability by appropriately adjusting thecapacitance of the first capacitor 450, the source resonator 410 mayalso be referred to as an MNG resonator. Various criteria may be appliedto determine the capacitance of the first capacitor 450. For example,the various criteria may include a criterion for enabling the sourceresonator 410 to have the characteristic of the metamaterial, acriterion for enabling the source resonator 410 to have a negativemagnetic permeability in a target frequency, a criterion for enablingthe source resonator 410 to have a zeroth order resonance characteristicin the target frequency, and/or the like. Based on at least onecriterion among the aforementioned criteria, the capacitance of thefirst capacitor 450 may be determined.

The source resonator 410, also referred to as the MNG resonator 410, mayhave a zeroth order resonance characteristic of having, as a resonancefrequency, a frequency when a propagation constant is “0”. Because thesource resonator 410 may have the zeroth order resonance characteristic,the resonance frequency may be independent with respect to a physicalsize of the MNG resonator 410. By appropriately designing the firstcapacitor 450, the MNG resonator 410 may sufficiently change theresonance frequency. Accordingly, the physical size of the MNG resonator410 may not be changed.

In a near field, the electric field may be concentrated on the firstcapacitor 450 inserted into the first transmission line. Accordingly,due to the first capacitor 450, the magnetic field may become dominantin the near field. The MNG resonator 410 may have a relatively highQ-factor using the first capacitor 450 of the lumped element, and thus,it is possible to enhance an efficiency of power transmission. Forexample, the Q-factor may indicate a level of an ohmic loss or a ratioof a reactance with respect to a resistance in the wireless powertransmission. The efficiency of the wireless power transmission mayincrease according to an increase in the Q-factor.

In some embodiments, a magnetic core may be further provided to passthrough the MNG resonator 410. The magnetic core may increase the powertransmission distance.

Referring to FIG. 4B, the feeding unit 420 may include a secondtransmission line, a third conductor 471, a fourth conductor 472, afifth conductor 481, and a sixth conductor 482.

The second transmission line may include a third signal conductingportion 461 and a fourth signal conducting portion 462 in an upperportion of the second transmission line. In addition, the secondtransmission line may include a second ground conducting portion 463 ina lower portion of the second transmission line. The third signalconducting portion 461 and the fourth signal conducting portion 462 maybe disposed to face the second ground conducting portion 463. Currentmay flow through the third signal conducting portion 461 and the fourthsignal conducting portion 462.

Additionally, one end of the third signal conducting portion 461 may beshorted to the third conductor 471, and another end of the third signalconducting portion 461 may be connected to the fifth conductor 481. Oneend of the fourth signal conducting portion 462 may be shorted to thefourth conductor 472, and another end of the fourth signal conductingportion 462 may be connected to the sixth conductor 482. The fifthconductor 481 may be connected to the first signal conducting portion431, and the sixth conductor 482 may be connected to the second signalconducting portion 432. The fifth conductor 481 and the sixth conductor482 may be connected in parallel to both ends of the first capacitor450. As shown, the fifth conductor 481 and the sixth conductor 482 maybe used as input ports to receive an input of an RF signal.

Accordingly, the third signal conducting portion 461, the fourth signalconducting portion 462, the second ground conducting portion 463, thethird conductor 471, the fourth conductor 472, the fifth conductor 481,the sixth conductor 482, and the source resonator 410 may be connectedto each other so that the source resonator 410 and the feeding unit 420may have an electrically closed-loop structure. When an RF signal isreceived via the fifth conductor 481 or the sixth conductor 482, aninput current may flow in the feeding unit 420 and the source resonator410, a magnetic field may be formed due to the input current, and acurrent may be induced to the source resonator 410 by the formedmagnetic field. A direction of the input current flowing in the feedingunit 420 may be identical to a direction of the induced current flowingin the source resonator 410 and thus, strength of the total magneticfield may increase in the center of the source resonator 410, but maydecrease outside the source resonator 410. The direction of the inputcurrent and the direction of the induced current will be furtherdescribed with reference to FIGS. 5A and 5B.

An input impedance may be determined based on an area of a regionbetween the source resonator 410 and the feeding unit 420 andaccordingly, a separate matching network used to match the inputimpedance to an output impedance of a power amplifier may not berequired. For example, even when the matching network is used, the inputimpedance may be determined by adjusting a size of the feeding unit 420and thus, a structure of the matching network may be simplified. Thesimplified structure of the matching network may minimize a matchingloss of the matching network.

The second transmission line, the third conductor 471, the fourthconductor 472, the fifth conductor 481, and the sixth conductor 482 mayform the same structure as the source resonator 410. When the sourceresonator 410 has a loop structure, the feeding unit 420 may also have aloop structure. For example, if the source resonator 410 has a circularstructure, the feeding unit 420 may also have a circular structure.

The above-described configuration of the source resonator 410 andconfiguration of the feeding unit 420 may be similarly applied to thetarget resonator and the feeding unit of the target resonator,respectively. When the feeding unit of the target resonator isconfigured as described above, the feeding unit may match an outputimpedance of the target resonator and an input impedance of the feedingunit, by adjusting a size of the feeding unit. Accordingly, a separatematching network may not be used.

FIG. 5A illustrates a distribution of a magnetic field within a sourceresonator based on feeding of a feeding unit. FIG. 5B illustrates anequivalent circuit of a feeding unit 540, and an equivalent circuit of asource resonator 550.

As used herein, a feeding operation may refer to supplying a power to asource resonator in a wireless power transmitter, or refer to supplyingan AC power to a rectification unit in a wireless power receiver. FIG.5A illustrates a direction of an input current flowing in the feedingunit, and a direction of an induced current induced in the sourceresonator. Additionally, FIG. 5A illustrates a direction of a magneticfield formed due to the input current of the feeding unit, and adirection of a magnetic field formed due to the induced current of thesource resonator.

Referring to FIG. 5A, a fifth conductor or a sixth conductor of thefeeding unit may be used as an input port 510. The input port 510 mayreceive an input of an RF signal. The RF signal may be output from apower amplifier. The power amplifier may increase or decrease theamplitude of the RF signal, on demand by a target device. The RF signalreceived by the input port 510 may form an input current flowing in thefeeding unit, with the input current flowing in a clockwise direction inthe feeding unit, along a transmission line of the feeding unit, forinstance. The fifth conductor of the feeding unit may be electricallyconnected to the source resonator. In one embodiment, the fifthconductor may be connected to a first signal conducting portion of thesource resonator. Accordingly, the input current may flow in the sourceresonator, as well as, in the feeding unit.

The input current may flow in a counterclockwise direction in the sourceresonator. The input current flowing in the source resonator may cause amagnetic field to be formed so that an induced current may be generatedin the source resonator due to the magnetic field. The induced currentmay flow in a clockwise direction in the source resonator. Here, theinduced current may transfer energy to a capacitor of the sourceresonator, and a magnetic field may be formed due to the inducedcurrent. The input current flowing in the feeding unit and the sourceresonator may be indicated by a solid line of FIG. 5A, and the inducedcurrent flowing in the source resonator may be indicated by a dottedline of FIG. 5A.

The direction of a magnetic field formed due to a current may bedetermined based on the right hand rule. As illustrated in FIG. 5A,within the feeding unit, the direction 521 of a magnetic field formeddue to the input current flowing in the feeding unit may be identical tothe direction 523 of a magnetic field formed due to the induced currentflowing in the source resonator. Accordingly, strength of the totalmagnetic field may increase within the feeding unit.

Additionally, in a region between the feeding unit and the sourceresonator, the direction 533 of a magnetic field formed due to the inputcurrent flowing in the feeding unit has a phase opposite to the phase ofa direction 531 of a magnetic field formed due to the induced currentflowing in the source resonator, as illustrated in FIG. 5A. Accordingly,the strength of the total magnetic field may decrease in the regionbetween the feeding unit and the source resonator.

Typically, the strength of a magnetic field decreases in the center of asource resonator with the loop structure, and increases outside thesource resonator. However, referring to FIG. 5A, the feeding unit may beelectrically connected to both ends of a capacitor of the sourceresonator, and accordingly the induced current of the source resonatormay flow in the same direction as the input current of the feeding unit.Since the induced current of the source resonator flows in the samedirection as the input current of the feeding unit, the strength of thetotal magnetic field may increase within the feeding unit, and maydecrease outside the feeding unit. As a result, the strength of thetotal magnetic field may increase in the center of the source resonatorwith the loop structure, and may decrease outside the source resonator,due to the feeding unit. Thus, the strength of the total magnetic fieldmay be equalized within the source resonator. Additionally, the powertransmission efficiency for transferring a power from the sourceresonator to a target resonator may be in proportion to the strength ofthe total magnetic field formed in the source resonator. And when thestrength of the total magnetic field increases in the center of thesource resonator, the power transmission efficiency may also increase.

Referring to FIG. 5B, the feeding unit 540 and the source resonator 550may be expressed by the equivalent circuits. Input impedance Z_(in),viewed in a direction from the feeding unit 540 to the source resonator550, may be computed according to Equation 1 as follows:

$\begin{matrix}{Z_{i\; n} = \frac{\left( {\omega\; M} \right)^{2}}{Z}} & \left\lbrack {{Equation}\mspace{14mu} 1} \right\rbrack\end{matrix}$

In Equation 1, M denotes a mutual inductance between the feeding unit540 and the source resonator 550, ω denotes a resonance frequencybetween the feeding unit 540 and the source resonator 550, and Z denotesthe impedance viewed in a direction from the source resonator 550 to atarget device. The input impedance Z_(in) may be in proportion to themutual inductance M. Accordingly, the input impedance Z_(in) may becontrolled by adjusting the mutual inductance M. The mutual inductance Mmay be adjusted based on an area of a region between the feeding unit540 and the source resonator 550. The area of the region between thefeeding unit 540 and the source resonator 550 may be adjusted based on asize of the feeding unit 540. And, the input impedance Z_(in) may bedetermined based on the size of the feeding unit 540. Thus, a separatematching network may not be required to perform impedance matching withan output impedance of a power amplifier.

In a target resonator and a feeding unit included in a wireless powerreceiver, a magnetic field may be distributed as illustrated in FIG. 5A.For example, the target resonator may receive a wireless power from asource resonator, using magnetic coupling. Due to the received wirelesspower, an induced current may be generated in the target resonator. Amagnetic field formed due to the induced current in the target resonatormay cause another induced current to be generated in the feeding unit.When the target resonator is connected to the feeding unit asillustrated in FIG. 5A, the induced current generated in the targetresonator may flow in the same direction as the induced currentgenerated in the feeding unit. Thus, strength of the total magneticfield may increase within the feeding unit, but may decrease in a regionbetween the feeding unit and the target resonator.

FIG. 6 illustrates another wireless power transmitter.

A controller 640 may adjust a mutual inductance M between the feedingunit and the source resonator, by adjusting an area of a region 610between a feeding unit and a source resonator. By adjusting the mutualinductance M, the controller 640 may determine a value of an inputimpedance Z_(in). The area of the region 610 may be adjusted bycontrolling a size of the feeding unit. The size of the feeding unit maybe determined based on a distance 620 between a fourth signal conductingportion and a second ground conducting portion, or based on a distance630 between a third conductor and a fourth conductor.

When the area of the region 610 is increased, the mutual inductance Mmay be increased. Conversely, when area of the region 610 is reduced,the mutual inductance M may be reduced. The controller 640 may beconfigured to determine the value of the input impedance Z_(in), byadjusting the size of the feeding unit. For example, in variousembodiments, the value of the input impedance Z_(in) may be adjustedfrom about 1 ohm (Ω) to 3000Ω, based on the size of the feeding unit.Accordingly, the controller 640 may match the input impedance Z_(in) toan output impedance of a power amplifier, based on the size of thefeeding unit. In some instances, the controller 640 may not need toemploy a separate matching network to perform impedance matching betweenthe input impedance 4, and the output impedance of the power amplifier.For example, when the output impedance of the power amplifier has avalue of 50Ω, the controller 640 may adjust the input impedance Z_(in)to 50Ω, by adjusting the size of the feeding unit. Additionally, even ifa matching network is used for an efficiency of matching, the controller640 may minimize a loss of power transmission efficiency by simplifyinga structure of the matching network.

The controller 640 may control a magnetic field formed in the sourceresonator to be uniformly distributed, based on a direction of aninduced current flowing in the source resonator, and a direction of aninput current flowing in the feeding unit. Since the feeding unit andthe source resonator are electrically connected to both ends of acapacitor, the induced current may be flow in the source resonator inthe same direction as the input current. The controller 640 may adjustthe size of the feeding unit based on distribution of the magnetic fieldin the source resonator, to strengthen a portion of the magnetic fieldwith a low strength, or to weaken a portion of the magnetic field with ahigh strength, so that the magnetic field may be uniformly distributed.This is because the controller 640 may enable strength of the totalmagnetic field to increase within the feeding unit, and enable thestrength of the magnetic field to decrease in the region 610 between thefeeding unit and the source resonator.

When the magnetic field is uniformly distributed in the sourceresonator, the source resonator may have a constant input impedancevalue. Due to the constant input impedance value, the wireless powertransmitter may prevent the power transmission efficiency from beingreduced, and may effectively transmit a power to the target device,regardless of a location of the target device on the source resonator.

A wireless power receiver may also include a target resonator, a feedingunit, and a controller. The controller may control an output impedanceof the target resonator, by adjusting a size of the feeding unit. Thecontroller 640 may be configured to match the output impedance of thetarget resonator to an input impedance of the feeding unit, by adjustingan area of a region between the target resonator and the feeding unit.The output impedance of the target resonator may refer to impedanceviewed in a direction from the target resonator to the source resonator.The input impedance of the feeding unit may refer to an impedance viewedin a direction from the feeding unit to a load.

FIG. 7 illustrates still another wireless power transmitter.

Referring to FIG. 7, source resonators 720 and 740 may be implemented asspiral resonators. Each of the spiral resonators may be configured bywinding a coil a plurality of times (e.g., “n” times) in a generallyspiral shape.

In FIG. 7, a feeding unit 710 may be disposed in the source resonator720, in particular, in an innermost turn of the coil wound in the spiralshape. The feeding unit 710 may include an input port 711 that receivesan input of an RF signal, and may enable an input current to flow in thefeeding unit 710. The input current may also flow in the sourceresonator 720, and may cause a magnetic field to be formed.Additionally, the magnetic field may enable an induced current to begenerated in the source resonator 720 in the same direction as the inputcurrent.

One of both of the source resonators 720 and 740 may include acapacitor. The capacitor may be electrically connected between a windingstarting end of the coil and a winding finishing end of the coil.

Additionally, a feeding unit 730 may be disposed around the sourceresonator 740. As shown, the feeding unit 730 may be positioned outsideof the outermost turn of the coil wound in the spiral shape. The feedingunit 730 may include an input port 731. The input port 731 may receivean input of an RF signal, and may enable an input current to flow in thefeeding unit 730. The input current may also flow in the sourceresonator 740, and may cause a magnetic field to be formed.Additionally, the magnetic field may enable an induced current to begenerated in the source resonator 740 in the same direction as the inputcurrent.

A source resonator may be formed in various shapes, for example, ameta-resonator, a coil resonator, a spiral resonator, a helicalresonator, or the like. Additionally, a feeding unit enabling an inducedcurrent to be generated in the source resonator may be located within oroutside the source resonator with the various shapes. For instance, thefeeding unit may be electrically connected to both ends of a capacitorincluded in the source resonator. Portions of the feeding unit that areelectrically connected to both ends of the capacitor may not enable aninput current to pass directly through the capacitor. The input currentmay flow through a loop formed by the feeding unit and the sourceresonator.

FIGS. 8A through 13B illustrate various resonators. A source resonatorincluded in a wireless power transmitter, and a target resonatorincluded in a wireless power receiver may be configured as illustratedin FIGS. 8A through 13B, for instance.

FIGS. 8A and 8B illustrate examples of a resonator having athree-dimensional (3D) structure.

Referring to FIG. 8A, a resonator 800 having the 3D structure mayinclude a transmission line and a capacitor 820. The transmission linemay include a first signal conducting portion 811, a second signalconducting portion 812, and a ground conducting portion 813. Thecapacitor 820 may be inserted, for instance, in series between the firstsignal conducting portion 811 and the second signal conducting portion812 of the transmission link such that an electric field may be confinedwithin the capacitor 820.

As illustrated in FIG. 8A, the resonator 800 may have a generally 3Dstructure. The transmission line may include the first signal conductingportion 811 and the second signal conducting portion 812 in an upperportion of the resonator 800, and may include the ground conductingportion 813 in a lower portion of the resonator 800. The first signalconducting portion 811 and the second signal conducting portion 812 maybe disposed to face the ground conducting portion 813. In thisarrangement, current may flow in an x direction through the first signalconducting portion 811 and the second signal conducting portion 812. Dueto the current, a magnetic field H(W) may be formed in a −y direction.However, it will be appreciated that the magnetic field H(W) might alsobe formed in the opposite direction (e.g., a +y direction) in otherimplementations.

In one or more embodiments, one end of the first signal conductingportion 811 may be electrically connected to (i.e., shorted) to aconductor 842, and another end of the first signal conducting portion811 may be connected to the capacitor 820. One end of the second signalconducting portion 812 may be grounded to a conductor 841, and anotherend of the second signal conducting portion 812 may be connected to thecapacitor 820. Accordingly, the first signal conducting portion 811, thesecond signal conducting portion 812, the ground conducting portion 813,and the conductors 841 and 842 may be connected to each other, wherebythe resonator 800 may have an electrically closed-loop structure.

As illustrated in FIG. 8A, the capacitor 820 may be inserted orotherwise positioned between the first signal conducting portion 811 andthe second signal conducting portion 812. The capacitor 820 may include,for example, a lumped element, a distributed element, or the like. Inone implementation, a distributed capacitor having the shape of thedistributed element may include zigzagged conductor lines and adielectric material having a relatively high permittivity positionedbetween the zigzagged conductor lines.

When the capacitor 820 is inserted into the transmission line, theresonator 800 may have a characteristic of a metamaterial, in someinstances.

For example, when the capacitance of the capacitor inserted as a lumpedelement is appropriately determined, the resonator 800 may have thecharacteristic of the metamaterial. When the resonator 800 has anegative magnetic permeability by appropriately adjusting thecapacitance of the capacitor 820, the resonator 800 may also be referredto as an MNG resonator. Various criteria may be applied to determine thecapacitance of the capacitor 820. For example, the various criteria mayinclude one or more of the following: a criterion to enable theresonator 800 to have the characteristic of the metamaterial, acriterion to enable the resonator 800 to have a negative magneticpermeability in a target frequency, a criterion to enable the resonator800 to have a zeroth order resonance characteristic in the targetfrequency, and/or the like. Based on at least one criterion among theaforementioned criteria, the capacitance of the capacitor 820 may bedetermined.

The resonator 800, also referred to as the MNG resonator 800, may have azeroth order resonance characteristic (i.e., having, as a resonancefrequency, a frequency when a propagation constant is “0”). If theresonator 800 has a zeroth order resonance characteristic, the resonancefrequency may be independent with respect to a physical size of the MNGresonator 800. Thus, by appropriately designing the capacitor 820, theMNG resonator 800 may sufficiently change the resonance frequencywithout substantially changing the physical size of the MNG resonator800.

Referring to the MNG resonator 800 of FIG. 8A, in a near field, theelectric field may be concentrated on the capacitor 820 inserted intothe transmission line. Accordingly, due to the capacitor 820, themagnetic field may become dominant in the near field. And, since the MNGresonator 800 having the zeroth-order resonance characteristic may havecharacteristics similar to a magnetic dipole, the magnetic field maybecome dominant in the near field. A relatively small amount of theelectric field formed due to the insertion of the capacitor 820 may beconcentrated on the capacitor 820 and thus, the magnetic field maybecome further dominant. The MNG resonator 800 may have a relativelyhigh Q-factor using the capacitor 820 of the lumped element and thus, itis possible to enhance an efficiency of power transmission.

Also, the MNG resonator 800 may include a matcher 830 to be used inimpedance matching. The matcher 830 may be configured to appropriatelyadjust the strength of the magnetic field of the MNG resonator 800. Theimpedance of the MNG resonator 800 may be determined by the matcher 830.In one or more embodiments, current may flow in the MNG resonator 800via a connector 840, or may flow out from the MNG resonator 800 via theconnector 840. And the connector 840 may be connected to the groundconducting portion 813 or the matcher 830.

As illustrated in FIG. 8A, the matcher 830 may be positioned within theloop formed by the loop structure of the resonator 800. The matcher 830may be configured to adjust the impedance of the resonator 800 bychanging the physical shape of the matcher 830. For example, the matcher830 may include a conductor 831 to be used in the impedance matching ina location separate from the ground conducting portion 813 by a distanceh. The impedance of the resonator 800 may be changed by adjusting thedistance h.

In some embodiments, a controller may be provided to control the matcher830. In this case, the matcher 830 may change the physical shape of thematcher 830 based on a control signal generated by the controller. Forexample, the distance h between the conductor 831 of the matcher 830 andthe ground conducting portion 813 may be increased or decreased based onthe control signal. Accordingly, the physical shape of the matcher 830may be changed such that the impedance of the resonator 800 may beadjusted. The distance h between the conductor 831 of the matcher 830and the ground conducting portion 813 may be adjusted using a variety ofschemes. Alternatively or additionally, a plurality of conductors may beincluded in the matcher 830 and the distance h may be adjusted byadaptively activating one of the conductors. For instance, the distanceh may be adjusted by adjusting the physical location of the conductor831 up and down. The distance h may be controlled based on the controlsignal of the controller. The controller may generate the control signalusing various factors.

As illustrated in FIG. 8A, the matcher 830 may be configured as apassive element such as the conductor 831, for instance. Of course, inother embodiments, the matcher 830 may be configured as an activeelement such as a diode, a transistor, or the like. When the activeelement is included in the matcher 830, the active element may be drivenbased on the control signal generated by the controller, and theimpedance of the resonator 800 may be adjusted based on the controlsignal. For example, if the active element is a diode included in thematcher 830, the impedance of the resonator 800 may be adjusteddepending on whether the diode is in an ON state or in an OFF state.

In some embodiments, a magnetic core may be further provided to passthrough the resonator 800 configured as the MNG resonator 800. Themagnetic core may perform a function of increasing a power transmissiondistance.

In addition, the resonator 800 may include a matcher 850 for impedancematching, as illustrate in FIG. 8B. The matcher 850 may include atransmission line, and conductors 854 and 855. The transmission line mayinclude a third signal conducting portion 851, a fourth signalconducting portion 852, and a ground conducting portion 853. Theconductor 854 may connect the third signal conducting portion 851 andthe ground conducting portion 853, and the conductor 855 may connect thefourth signal conducting portion 852 and the ground conducting portion853. The third signal conducting portion 851 and the fourth signalconducting portion 852 may be connected to both ends of the capacitor820 of the resonator 800.

Additionally, one end of the third signal conducting portion 851 may beshorted to the conductor 854, and another end of the third signalconducting portion 851 may be connected to one end of the capacitor 820.One end of the fourth signal conducting portion 852 may be electricallyconnected (e.g., shorted) to the conductor 855, and another end of thefourth signal conducting portion 852 may be connected to another end ofthe capacitor 820.

Accordingly, the matcher 850 and the resonator 800 may be connected toeach other, whereby the resonator 800 may have an electricallyclosed-loop structure. The matcher 850 may appropriately adjust strengthof a magnetic field in the resonator 800. An impedance of the resonator800 may be determined by the matcher 850. Additionally, a current mayflow into and/or out of the resonator 800 via the connector 840. Theconnector 840 may be connected to the matcher 850. For instance, theconnector 840 may be connected to the third signal conducting portion851 or the fourth signal conducting portion 852. The current flowinginto the resonator 800 via the connector 840 may cause an inducedcurrent to be generated in the resonator 800. Accordingly, the directionof a magnetic field formed by the resonator 800 may be identical to thedirection of a magnetic field formed by the matcher 850 and thus, thestrength of the total magnetic field may increase within the matcher850. Conversely, the direction of a magnetic field formed by theresonator 800 may be opposite to the direction of a magnetic fieldformed by the matcher 850 and thus, the strength of the total magneticfield may decrease outside the matcher 850.

The matcher 850 may adjust an impedance of the resonator 800 by changingthe physical shape of the matcher 850. For example, the matcher 850 mayinclude the third signal conducting portion 851 and the fourth signalconducting portion 852 for the impedance matching in a location that isseparated from the ground conducting portion 853 by a distance h. Theimpedance of the resonator 800 may be changed by adjusting the distanceh.

In some embodiments, a controller may be provided to control the matcher850. For example, the matcher 850 may be configured to change thephysical shape of the matcher 850 based on a control signal generated bythe controller. For example, the distance h between the groundconducting portion 853, and the third signal conducting portion 851 andthe fourth signal conducting portion 852 of the matcher 850 may increaseor decrease based on the control signal. Accordingly, the physical shapeof the matcher 850 may be changed, and the impedance of the resonator800 may be adjusted. The distance h between the ground conductingportion 853, and the third signal conducting portion 851 and the fourthsignal conducting portion 852 of the matcher 850 may be adjusted using avariety of schemes. As one example, a plurality of conductors may beincluded in the matcher 850 and the distance h may be adjusted byadaptively activating one of the conductors. As another example, thedistance h may be adjusted by adjusting the physical locations of thethird signal conducting portion 851 and the fourth signal conductingportion 852 up and down. The distance h may be controlled based on thecontrol signal of the controller. The controller may generate thecontrol signal using various factors. Additionally, a distance w betweenthe conductors 854 and 855 of the matcher 850 may increase or decreasebased on the control signal. Accordingly, the physical shape of thematcher 850 may be changed and the impedance of the resonator 800 may beadjusted.

FIGS. 9A and 9B illustrate examples of a bulky-type resonator forwireless power transmission.

Referring to FIG. 9A, a first signal conducting portion 911 and aconductor 942 may be integrally formed, rather than being separatelymanufactured and being connected to each other. Similarly, a secondsignal conducting portion 912 and a conductor 941 may also be integrallymanufactured.

When the second signal conducting portion 912 and the conductor 941 areseparately manufactured and then are connected to each other, a loss ofconduction may occur due to a seam 950. Thus, in some implementations,the second signal conducting portion 912 and the conductor 941 may beconnected to each other without using a separate seam (i.e., seamlesslyconnected to each other). Additionally, the conductor 941 and a groundconducting portion 913 may be seamlessly connected to each other.Accordingly, it is possible to decrease a conductor loss caused by theseam 950. For instance, the second signal conducting portion 912 and theground conducting portion 913 may be seamlessly and integrallymanufactured. Similarly, the first signal conducting portion 911, theconductor 942 and the ground conducting portion 913 may be seamlesslyand integrally manufactured.

Referring to FIG. 9A, a type of a seamless connection connecting atleast two partitions into an integrated form is referred to as a bulkytype.

As used herein, the term “bulky type” may refer to a seamless connectionconnecting at least two parts in an integrated form.

The resonator 900 may include a matcher 930, as illustrated in FIG. 9A.For example, the resonator 900 may include a matcher 960, as illustratedin FIG. 9B, with, conduction portions 961 and 962 of the matcher 960 maybe connected to the capacitor 920.

FIGS. 10A and 10B illustrate a hollow-type resonator for wireless powertransmission.

Referring to FIG. 10A, each of a first signal conducting portion 1011, asecond signal conducting portion 1012, a ground conducting portion 1013,and conductors 1041 and 1042 of a resonator 1000 configured as thehollow type structure. As used herein, the term “hollow type” refers toa configuration that may include an empty space inside.

For a given resonance frequency, an active current may be modeled to inonly a portion of the first signal conducting portion 1011 instead ofthe entire first signal conducting portion 1011, may be modeled to flowin only a portion of the second signal conducting portion 1012 insteadof the entire second signal conducting portion 1012, may be modeled toflow in only a portion of the ground conducting portion 1013 instead ofthe entire ground conducting portion 1013, and/or may be modeled to flowin only a portion of the conductors 1041 and 1042 instead of the entireconductors 1041 and 1042. When a depth of the first signal conductingportion 1011, the second signal conducting portion 1012, the groundconducting portion 1013, and the conductors 1041 and 1042 may besignificantly deeper than a corresponding skin depth in the givenresonance frequency, it may be ineffective. The significantly deeperdepth, however, may increase the weight or manufacturing costs of theresonator 1000, in some instances.

Accordingly, for the given resonance frequency, the depth of each of thefirst signal conducting portion 1011, the second signal conductingportion 1012, the ground conducting portion 1013, and the conductors1041 and 1042 may be appropriately determined based on the correspondingskin depth of each of the first signal conducting portion 1011, thesecond signal conducting portion 1012, the ground conducting portion1013, and the conductors 1041 and 1042. When the first signal conductingportion 1011, the second signal conducting portion 1012, the groundconducting portion 1013, and the conductors 1041 and 1042 has anappropriate depth deeper than a corresponding skin depth, the resonator1000 may be manufactured to be lighter in weight, and manufacturingcosts of the resonator 1000 may also decrease.

For example, as illustrated in FIG. 10A, the depth of the second signalconducting portion 1012 (as further illustrated in the enlarged viewregion 1060 indicated by a circle) may be determined as “d” mm, and dmay be determined according to

$d = {\frac{1}{\sqrt{\pi\; f\;\mu\;\sigma}}.}$Here, f denotes a frequency, μ denotes a magnetic permeability, and σdenotes a conductor constant. In one implementation, when the firstsignal conducting portion 1011, the second signal conducting portion1012, the ground conducting portion 1013, and the conductors 1041 and1042 are made of copper and they may have a conductivity of 5.8×10⁷siemens per meter (S·m⁻¹), the skin depth may be about 0.6 mm withrespect to 10 kHz of the resonance frequency, and the skin depth may beabout 0.006 mm with respect to 100 MHz of the resonance frequency.

The resonator 1000 may include a matcher 1030, as illustrated in FIG.10A.

For example, the resonator 1000 may include a matcher 1050, asillustrated in FIG. 10B with conduction portions 1051 and 1052 of thematcher 1050 may be connected to the capacitor 1020.

FIGS. 11A and 11B illustrate a resonator for wireless power transmissionusing a parallel-sheet configuration.

Referring to FIG. 11A, the parallel-sheet configuration may beapplicable to a first signal conducting portion 1111 and a second signalconducting portion 1112 included in a resonator 1100.

Each of the first signal conducting portion 1111 and the second signalconducting portion 1112 may not be a perfect conductor, and thus mayhave an inherent resistance. Due to this resistance, an ohmic loss mayoccur. The ohmic loss may decrease a Q-factor and may also decrease acoupling effect.

By applying the parallel-sheet configuration to each of the first signalconducting portion 1111 and the second signal conducting portion 1112,it may be possible to decrease the ohmic loss, and to increase theQ-factor and the coupling effect. Referring to the enlarged view portion1170 indicated by a circle in FIG. 11A, when the parallel-sheetconfiguration is applied, the first signal conducting portion 1111 andthe second signal conducting portion 1112 may include a plurality ofconductor lines. The plurality of conductor lines may be disposed inparallel, and may be electrically connected (i.e., shorted) at an endportion of each of the first signal conducting portion 1111 and thesecond signal conducting portion 1112.

When the parallel-sheet configuration is applied to each of the firstsignal conducting portion 1111 and the second signal conducting portion1112, the plurality of conductor lines may be disposed in parallel.Accordingly, the sum of resistances of the conductor lines may decrease.Consequently, the resistance loss may decrease, and the Q-factor and thecoupling effect may increase.

The resonator 1100 may include a matcher 1130, as illustrated in FIG.11A.

For example, the resonator 1100 may include a matcher 1150, asillustrated in FIG. 11B, with conduction portions 1151 and 1152 of thematcher 1150 may be connected to the capacitor 1120.

FIGS. 12A and 12B illustrate a resonator for wireless power transmissionincluding a distributed capacitor.

Referring to FIG. 12A, a capacitor 1220 included in a resonator 1200 isconfigured for the wireless power transmission. A capacitor may beconfigured as a lumped element and may have a relatively high equivalentseries resistance (ESR). A variety of schemes have been proposed todecrease the ESR contained in the capacitor of the lumped element.According to an example embodiment, by using the capacitor 1220 as adistributed element, it may be possible to decrease the ESR. As will beappreciated, a loss caused by the ESR may decrease a Q-factor and acoupling effect.

As illustrated in FIG. 12A, the capacitor 1220 may be configured with azigzagged conductive line and a dielectric material.

By employing the capacitor 1220 as the distributed element, it may bepossible to decrease the loss occurring due to the ESR in someinstances. In addition, by disposing, in parallel, a plurality ofcapacitors as lumped elements, it may be possible to decrease the lossoccurring due to the ESR. Since a resistance of each of the capacitorsas the lumped elements decreases through a parallel connection, activeresistances of parallel-connected capacitors as the lumped elements mayalso decrease, whereby the loss occurring due to the ESR may decrease.For example, by employing ten capacitors of 1 pF each instead of using asingle capacitor of 10 pF, it may be possible to decrease the lossoccurring due to the ESR in some instances.

As illustrated in FIG. 12B, the resonator 1200 may include a matcher1230. Conduction portions 1231 and 1232 of the matcher 1230 may beconnected to the capacitor 1220.

FIG. 13A illustrates a matcher used in a resonator having the 2Dstructure, and FIG. 13B illustrates an example of a matcher used in aresonator having the 3D structure.

FIG. 13A illustrates a portion of a resonator 1300 including a matcher1330, and FIG. 13B illustrates a portion of the resonator 800 of FIG. 8Aincluding the matcher 830.

Referring to FIG. 13A, the matcher 1330 includes a conductor 1331, aconductor 1332, and a conductor 1333. The conductors 1332 and 1333 maybe connected to the conductor 1331, and to a first ground conductingportion 1313 of a transmission line. The matcher 1330 may correspond tothe feeder 360 of FIG. 3B. The impedance of the 2D resonator may bedetermined based on a distance h between the conductor 1331 and thefirst ground conducting portion 1313. The distance h between theconductor 1331 and the first ground conducting portion 1313 may becontrolled by a controller. The distance h between the conductor 1331and the first ground conducting portion 1313 may be adjusted using avariety of schemes. For example, the variety of schemes may include oneor more of the following: a scheme of adjusting the distance h byadaptively activating one of the conductors 1331, 1332, and 1333, ascheme of adjusting the physical location of the conductor 1331 up anddown, or the like.

Referring to FIG. 13B, the matcher 830 includes the conductor 831, aconductor 832, a conductor 833 and conductors 841 and 842. Theconductors 832 and 833 may be connected to the ground conducting portion813 and the conductor 831. The impedance of the 3D resonator may bedetermined based on a distance h between the conductor 831 and theground conducting portion 813. The distance h between the conductor 831and the ground conducting portion 813 may be controlled by thecontroller, for example. Similar to the matcher 1330 of FIG. 13A, in thematcher 830, the distance h between the conductor 831 and the groundconducting portion 813 may be adjusted using a variety of schemes. Forexample, the variety of schemes may include one or more of thefollowing: a scheme of adjusting the distance h by adaptively activatingone of the conductors 831, 832, and 833, a scheme of adjusting thephysical location of the conductor 831 up and down, or the like.

In some implementations, the matcher may include an active element.Thus, a scheme of adjusting an impedance of a resonator using the activeelement may be similar to the examples described above. For example, theimpedance of the resonator may be adjusted by changing a path of acurrent flowing through the matcher using the active element.

FIG. 14 illustrates one equivalent circuit of the resonator 800 of FIG.8A.

The resonator 800 of FIG. 9 for a wireless power transmission may bemodeled to the equivalent circuit of FIG. 14. In the equivalent circuitdepicted in FIG. 14, L_(R) denotes an inductance of the powertransmission line, C_(L) denotes the capacitor 820 that is inserted in aform of a lumped element in the middle of the power transmission line,and C_(R) denotes a capacitance between the power transmissions and/orground of FIG. 8A.

In some instances, the resonator 800 may have a zeroth resonancecharacteristic. For example, when a propagation constant is “0”, theresonator 800 may be assumed to have ω_(MZR) as a resonance frequency.The resonance frequency ω_(MZR) may be expressed by Equation 2 asfollows:

$\begin{matrix}{\omega_{MZR} = \frac{1}{\sqrt{L_{R}C_{L}}}} & \left\lbrack {{Equation}\mspace{14mu} 2} \right\rbrack\end{matrix}$

In Equation 2, MZR denotes a Mu zero resonator.

Referring to Equation 2, the resonance frequency ω_(MZR) of theresonator 800 may be determined by L_(R)/C_(L). A physical size of theresonator 800 and the resonance frequency ω_(MZR) may be independentwith respect to each other. Since the physical sizes are independentwith respect to each other, the physical size of the resonator 800 maybe sufficiently reduced.

FIG. 15 illustrates a method for transmitting and receiving a wirelesspower.

Referring to FIG. 15, a first device, a second device, and a thirddevice may be implemented, for example, using the target device 120 ofFIG. 1, or the electronic device 220 of FIG. 2. Additionally, the firstdevice may be implemented, for example, by using the source device 110of FIG. 1. When the second device transmits a power to the third device,the second device may be referred to as a wireless power transmitter,and the third device may be referred to as a wireless power receiver.When the second device and the third device receive a powersimultaneously from the first device, the second device and the thirddevice may be referred to as wireless power receivers.

In operations 1510 or 1520, the first device, the second device, and thethird device perform communications with different electronic devices,and determine one of a plurality of operating modes by thecommunications including a power reception mode, a relay mode, and apower transmission mode, for instance.

For example, in 1510, the first device may perform a communication withthe second device and the third device, to perform authentication of thesecond device and the third device, or to check an amount of a powerrequired in each of the second device and the third device.

In operation 1531, the first device selects an operating mode of thefirst device. In operation 1532, the second device selects an operatingmode of the second device. In operation 1533, the third device selectsan operating mode of the third device. For example, the first device mayselect the power transmission mode as the operating mode. The seconddevice may select one of the relay mode, the power reception mode, orthe power transmission mode, as the operating mode. The third device mayselect a power reception mode as the operating mode.

In operation 1540, power transmission, power relay, and power receptionmay be performed. Specifically, in operation 1541, the first devicetransmits a power to the second device. In operation 1542, the seconddevice relays the power received from the first device to the thirddevice. Additionally, in operation 1542, the second device transmits thepower to the third device using a stored power. In some implementations,a plurality of electronic devices may be further located between thesecond device and the third device. A resonator of the third device mayreceive a power from the first device, namely a wireless powertransmitter, by passing through the plurality of electronic devices.Additionally, a resonator of the second device may transmit a power tothe third device, namely a wireless power receiver, by passing throughthe plurality of electronic devices. In operations 1541 and 1543, aresonator of the first device may simultaneously transmit a power to thesecond device and the third device. Thus, the resonator of the firstdevice may simultaneously transmit a power to the plurality ofelectronic devices.

In operation 1550, the second device and the third device transmit, tothe first device, reports for the received powers. For example, thereports may include information on an amount of a power received to aresonator.

In operation 1560, the first device may perform power control. The powercontrol may be performed to adjust a resonance frequency, and to adjustan impedance.

FIGS. 16 and 17 illustrate examples of a method for transmitting andreceiving wireless power between electronic devices.

Referring to FIG. 16, an electronic device 1610 may be implemented, forexample, using the source device 110 of FIG. 1, or the electronic device220 of FIG. 2. An electronic device 1640 may be implemented, forexample, using the target device 120 of FIG. 1, or the electronic device220 of FIG. 2. For example, the electronic device 1640 may receive apower from the electronic device 1610, via a plurality of electronicdevices, for example electronic devices 1620 and 1630. Thus, theelectronic devices 1620 and 1630 may be operated in the relay mode. Apower transfer path from the electronic device 1610 to the electronicdevice 1640 may be determined by communication, or may be set inadvance.

Referring to FIG. 17, an electronic device 1710 may be implemented, forexample, using the source device 110 of FIG. 1, or the electronic device220 of FIG. 2. Additionally, each of a plurality of electronic devices,for example electronic devices 1720, 1730, and 1740, may be implemented,for example, using the target device 120 of FIG. 1, or the electronicdevice 220 of FIG. 2. As illustrated in FIG. 17, power may besimultaneously transmitted from the electronic device 1710 to theelectronic devices 1720, 1730, and 1740.

FIG. 18 illustrates an electric vehicle charging system.

Referring to FIG. 18, an electric vehicle charging system 1800 includesa source system 1810, a source resonator 1820, a target resonator 1830,a target system 1840, and an electric vehicle battery 1850.

The electric vehicle charging system 1800 may have a similar structureto the wireless power transmission system of FIG. 1. The source system1810 and the source resonator 1820 in the electric vehicle chargingsystem 1800 may function as a source. Additionally, the target resonator1830 and the target system 1840 in the electric vehicle charging system1800 may function as a target.

The source system 1810 may include an alternating current-to-directcurrent (AC/DC) converter, a power detector, a power converter, acontrol/communication unit, similarly to the source 110 of FIG. 1. Thetarget system 1840 may include a rectification unit, a DC-to-DC (DC/DC)converter, a switch unit, a charging unit, and a control/communicationunit, similarly to the target 120 of FIG. 1.

The electric vehicle battery 1850 may be charged by the target system1840.

The electric vehicle charging system 1800 may use a resonant frequencyin a band of a few kilohertz (KHz) to tens of MHz.

The source system 1810 may generate power, based on a type of chargingvehicle, a capacity of a battery, and a charging state of a battery, andmay supply the generated power to the target system 1840.

The source system 1810 may control the source resonator 1820 and thetarget resonator 1830 to be aligned. For example, when the sourceresonator 1820 and the target resonator 1830 are not aligned, thecontroller of the source system 1810 may transmit a message to thetarget system 1840, and may control alignment between the sourceresonator 1820 and the target resonator 1830.

For example, when the target resonator 1830 is not located in a positionenabling maximum magnetic resonance, the source resonator 1820 and thetarget resonator 1830 may not be aligned. When a vehicle does not stopaccurately, the source system 1810 may induce a position of the vehicleto be adjusted, and may control the source resonator 1820 and the targetresonator 1830 to be aligned.

The source system 1810 and the target system 1840 may transmit orreceive an ID of a vehicle, or may exchange various messages, throughcommunication.

The descriptions of FIGS. 2 through 15 may be applied to the electricvehicle charging system 1800. However, the electric vehicle chargingsystem 1800 may use a resonant frequency in a band of a few KHz to tensof MHz, and may transmit power that is equal to or higher than tens ofwatts to charge the electric vehicle battery 1850.

FIG. 19 illustrates an example of a wireless power transmission methodof an electric vehicle.

In FIG. 19, wireless power transmission may be performed betweenelectric vehicles.

A first electric vehicle 1910 may be operated in a power transmissionmode, and a second electric vehicle 1920 may be operated in a powerreception mode.

The first electric vehicle 1910 may have the same configuration as theelectronic device 220 of FIG. 2. Additionally, the second electricvehicle 1920 may have the same configuration as the electronic device220 of FIG. 2. However, for convenience of description, the electronicdevice 220 is assumed to include the power converter 228, therectification unit 222, the DC/DC converter 223, the switch unit 224,the charging unit 225, the control/communication unit 226, and the pathcontroller 227, excluding the resonator 221.

The first electric vehicle 1910 may further include a source resonator1930 operated in the power transmission mode, and the second electricvehicle 1920 may further include a target resonator 1940 operated in thepower reception mode.

The charging unit 225 may be, for example, a battery mounted in anelectric vehicle. For example, the charging unit 225 may charge theelectric vehicle with power of at least tens of watts.

Additionally, the wireless power transmission between the first electricvehicle 1910 and the second electric vehicle 1920 may be performed viarepeaters 1950 and 1960.

The first electric vehicle 1910 may perform the wireless powertransmission using an external power source, or using power used tocharge a battery.

According to various embodiments, an electronic device may wirelesslyreceive a power, while wirelessly transmitting a power.

Additionally, an electronic device may wirelessly receive power supplywhen a power is required, regardless of a location.

The units described herein may be implemented using hardware componentsand software components. For example, a processing device may beimplemented using one or more general-purpose or special purposecomputers, such as, for example, a processor, a controller and anarithmetic logic unit, a digital signal processor, a microcomputer, afield programmable array, a programmable logic unit, a microprocessor orany other device capable of responding to and executing instructions ina defined manner. The processing device may run an operating system (OS)and one or more software applications that run on the OS. The processingdevice also may access, store, manipulate, process, and create data inresponse to execution of the software. For purpose of simplicity, thedescription of a processing device is used as singular; however, oneskilled in the art will appreciated that a processing device may includemultiple processing elements and multiple types of processing elements.For example, a processing device may include multiple processors or aprocessor and a controller. In addition, different processingconfigurations are possible, such a parallel processor.

The software may include a computer program, a piece of code, aninstruction, or some combination thereof, for independently orcollectively instructing or configuring the processing device to operateas desired. Software and data may be embodied permanently or temporarilyin any type of machine, component, physical or virtual equipment,computer storage medium or device, or in a propagated signal wavecapable of providing instructions or data to or being interpreted by theprocessing device. The software also may be distributed over networkcoupled computer systems so that the software is stored and executed ina distributed fashion. In particular, the software and data may bestored by one or more computer readable recording mediums. The computerreadable recording medium may include any data storage device that canstore data which can be thereafter read by a computer system orprocessing device. Examples of the computer readable recording mediuminclude read-only memory (ROM), random-access memory (RAM), CD-ROMs,magnetic tapes, floppy disks, optical data storage devices. Also,functional programs, codes, and code segments for accomplishing theexample embodiments disclosed herein can be easily construed byprogrammers skilled in the art to which the embodiments pertain based onand using the flow diagrams and block diagrams of the figures and theircorresponding descriptions as provided herein.

A number of examples have been described above. Nevertheless, it shouldbe understood that various modifications may be made. For example,suitable results may be achieved if the described techniques areperformed in a different order and/or if components in a describedsystem, architecture, device, or circuit are combined in a differentmanner and/or replaced or supplemented by other components or theirequivalents. Accordingly, other implementations are within the scope ofthe following claims.

What is claimed is:
 1. An electronic device for transmitting andreceiving wireless power, the electronic device comprising: a resonatorconfigured to operate, based on a plurality of operating modes of theelectronic device including a power reception mode, a relay mode, and apower transmission mode, wherein: (i) in the power reception mode, theresonator is configured to receive power from a wireless powertransmitter, (ii) in the relay mode, the resonator is configured torelay power received from the wireless power transmitter to a wirelesspower receiver, and (iii) in the power transmission mode, the resonatoris configured to transmit power to the wireless power receiver; and apath controller configured to control at least one electrical pathway ofelectronic device based on the operating mode.
 2. The electronic deviceof claim 1, further comprising: a power converter configured to convertdirect current (DC) voltage to alternating current (AC) voltage using aresonance frequency, and to transfer the AC current to the resonator,when the electronic device is operated in the power transmission mode.3. The electronic device of claim 2, further comprising a poweramplifier configured to amplify the DC voltage.
 4. The electronic deviceof claim 1, further comprising: a rectification unit configured togenerate a DC signal by rectifying an AC signal of a power received viathe resonator, when the electronic device is operated in the powerreception mode.
 5. The electronic device of claim 1, further comprising:a DC-to-DC (DC/DC) converter configured to supply voltage of apredetermined level to a load by adjusting a level of the DC signal. 6.The electronic device of claim 1, further comprising: acontrol/communication unit configured to perform a communication withthe wireless power transmitter or the wireless power receiver, todetermine the operating mode by the communication, to control the pathcontroller based on the determined operating mode, or any combinationthereof.
 7. The electronic device of claim 1, wherein the resonator isconfigured to receive the power from the wireless power transmitter bypassing through one or more electronic devices.
 8. The electronic deviceof claim 1, wherein the resonator is configured to transmit the power tothe wireless power receiver by passing through one or more electronicdevices.
 9. The electronic device of claim 1, wherein the resonator isconfigured to simultaneously transmit the power to a plurality ofelectronic devices.
 10. The electronic device of claim 1 furthercomprising: a control/communication unit configured to control amagnetic field to be uniformly distributed, based on a direction of aninduced current flowing in the resonator, and on a direction of an inputcurrent flowing in a feeding unit, wherein the magnetic field is formedin the resonator.
 11. A method for transmitting and receiving wirelesspower in an electronic device, the method comprising: determining one ofa plurality of operating modes of the electronic device, the pluralityof operating modes of the electronic device including a power receptionmode, a relay mode, and a power transmission mode; and (i) in the powerreception mode, receiving power from a wireless power transmitter, (ii)in the relay mode, relaying power received from the wireless powertransmitter to a wireless power receiver, and (iii) in the powertransmission mode, transmitting power to the wireless power receiver.12. The method of claim 11, further comprising: performing acommunication with another electronic device to determine the operatingmode of the electronic device.
 13. The method of claim 11, furthercomprising: supplying voltage of a predetermined level to a load byadjusting a level of a DC signal.
 14. The method of claim 11, furthercomprising: generating power using a resonance frequency; andtransferring the generated power to a resonator.
 15. The method of claim11, further comprising generating a DC signal by rectifying an AC signalof power received via a resonator.
 16. The method of claim 11, furthercomprising: receiving the power from the wireless power transmitter bypassing through one or more electronic devices.
 17. The method of claim11, further comprising: transmitting the power to the wireless powerreceiver by passing through one or more electronic devices.
 18. Themethod of claim 11, further comprising: simultaneously transmitting thepower to a plurality of electronic devices.
 19. A resonator devicecomprising: a feeder configured to receive an input current and to forma magnetic field; and a resonator configured to form another magneticfield based on an induced current generated by the magnetic field of thefeeder, wherein, when the magnetic field formed by the feeder and theanother magnetic field formed by the source resonator are combined, thestrength of the combined magnetic field changes within the feeder andoutside the feeder.
 20. The resonator device of claim 19, wherein: (i)the strength of the combined magnetic field decreases within the feederand increases outside the feeder; or (ii) the strength of the combinedmagnetic field increases within the feeder and deceases outside thefeeder.
 21. The resonator device of claim 19, wherein the resonator andthe feeder have a common ground.
 22. The resonator device of claim 19,wherein the resonator comprises a capacitor.
 23. The resonator of claim22, wherein the feeder is electrically connected to the capacitor. 24.The resonator of claim 19, wherein the feeder is positioned at leastpartially within the resonator.
 25. The resonator of claim 19, whereinthe resonator has a closed loop structure.
 26. The resonator of claim19, wherein the resonator comprises: a first transmission linecomprising a first signal conducting portion, a second signal conductingportion, and a first ground conducting portion, the first groundconducting portion corresponding to the first signal conducting portionand the second signal conducting portion; a first conductor electricallyconnecting the first signal conducting portion to the first groundconducting portion; a second conductor electrically connecting thesecond signal conducting portion to the first ground conducting portion;and at least one first capacitor inserted between the first signalconducting portion and the second signal conducting portion, in serieswith respect to a current flowing through the first signal conductingportion and the second signal conducting portion.
 27. The resonator ofclaim 19, wherein the feeder comprises: a second transmission linecomprising a third signal conducting portion, a fourth signal conductingportion, and a second ground conducting portion, the second groundconducting portion corresponding to the third signal conducting portionand the fourth signal conducting portion; a third conductor electricallyconnecting the third signal conducting portion to the second groundconducting portion; a fourth conductor electrically connecting thefourth signal conducting portion to the second ground conductingportion; a fifth conductor electrically connecting the first signalconducting portion to the third signal conducting portion; and a sixthconductor electrically connecting the second signal conducting portionto the fourth signal conducting portion.
 28. The resonator of claim 19,further comprising: a control/communication unit configured to controlthe magnetic field to be uniformly distributed, based on a direction ofan induced current flowing in the resonator, and on a direction of aninput current flowing in the feeder.
 29. The resonator of claim 28,wherein the controller is configured to adjust the size of the feeder.30. The resonator of claim 19, further comprising: a matching deviceconfigured to match the input impedance to an output impedance.